GMATMadeeasy wrote:

Question : \(a^b^c\)

How one will interpret this ?\((a^b)^c\) or \((a)^(b^c)\)

Second :

\((81)^1/4\) ; It is equivalent to 3 and or -3 in GMAT ? I am aware that \(\sqrt{(x^2)}\) is always positive value.

You would interpret \(a^b^c\) as \(a^(b^c)\) - the rule is to work 'top-down'. To me, it would feel 'funny' to evaluation a^b before evaluation b^c.

The second one confuses me:

\(\sqrt{(x^2)}\) is x always positive?

Take \(x=-2\) for example:

\((-2)^2= 4\)

\(\sqrt{4}=+2, -2\), so x could have been either positive or negative.

Hence, \((81)^1/4\) is +3 or -3, but you cannot tell from the equation.

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Andrew

http://www.RenoRaters.com